The present invention relates to method for discharging and applying flowable media under pressure for cosmetic, pharmaceutic, and technical purposes.
Several methods for discharging and applying flowable media under pressure are known. In accordance with one method a gas stream, for example, compressed air, passes through a nozzle and acts upon a liquid forwarded thereinto so as to break the liquid in form of drops to atomize the same. In order to generate the compressed air, expensive compressors are, however, necessary which involves operation with a stationary equipment. Furthermore, the drops of the broken liquid produced by this method have substantially not uniform dimensions. A portion of the liquid is always broken into drops with small dimensions which do not adhere to surfaces to be treated and contaminate the air as suspended particles. This leads, especially in small spaces, such as for example in barber shops, to bothering of customers and personnel and to dirtying of the equipment. This method makes possible to atomize two or more liquids with separate supply of the same. However, an accurate mixing ratio of the components relative to one another can be attained with difficulties and after complicated and time-consuming adjusting process, and the ratio cannot be reliably reproduced. Also, foaming of the liquids in accordance with this method is not possible. Generally speaking, the implementation of this method in small industrial shops and in household is hardly accepted.
It is further known to pack a liquid preparation together with a liquefied or gaseous motive gas in a pressure atomizing package, and to discharge the same via a discharge head provided with an outlet valve, as spray or as foam. The pressure atomizer packages are convenient, easy to transport and simple to utilize. However, they have the disadvantage in that they are utilized once, and therefore, the costs of the package and the motive gas are considerably high as compared with the costs of the liquid preparation. During the atomization according to this method, suspended particles are also generated which leads, similarly to the air operated atomizing devices, to troubles and contamination in the condition of frequent utilization of the devices. Fluorochlorhydrocarbon compounds which are generally utilized as motive gas are believed to be damaging for the environment. Also, the attempts to separate the motive gas into the pressure atomizer doses by bags or pistons were not successful in practice. In this construction reduction of the quantity of the motive gas and increase of the component of the flowable preparation, as well as the reduction of the quantity of the suspended particles, as compared with the normal spraying nozzles, can be attained. However, the cost of these packages, as compared with the normal aerosol doses, is uneconomically high because of the additional structural parts, the complicated and expensive filling, and the necessity of the utilization of the pressure atomizer doses with high pressure tightness. A further basic disadvantage of the above-described pressure atomizer packages is that in this packaging process it is commercially impossible to utilize slowly interacting materials which must be mixed shortly before the utilization in a predetermined ratio and then discharged as foam, such as for example, hair dyes.
It is further known to atomize liquids with the aid of finger pressure actuated atomizing pumps via a whirling chamber nozzle, in nearly mechanical manner without a motive gas. Such a method has, however, the disadvantage that the finger force becomes weaker very fast and thereby the atomizing is not continuous, but, instead, is intermittent. Therefore, a uniform wetting of the surfaces to be treated cannot be attained. It is also difficult to reach the locations which are not easy of access, for example, to reach the rear head region by hair spray preparations with simultaneous pump movement. The attempts to actuate the atomizing pumps not by hand, but by eccentrics driven by an electric motor, did not show the desirable results. The reason for this is that the weight of the arrangement because of the motor, gearing, batteries and housing makes the same inconvenient, additional motor noise generates, the disadvantageous intermittent atomizing takes place in this method, and the prime cost of the arrangement is too high as compared with the advantages thereof. In order to provide for a continuous spraying process with simultaneous atomizing without a motive gas, a further method was proposed. In accordance with this method, the liquid to be atomized is pumped before the discharge into a chamber which is sealed by a sleeve valve loaded at the opposite side by a prestressed spring. Then, the liquid which is held under pressure acting upon the sleeve valve is atomized via an outlet valve provided with a whirle spray head, until the sleeve valve attains its initial position. This arrangement has, however, the disadvantage in that the liquid pressure provided by the spring is too low for sufficient atomizing and in any event does not reach generally used medium pressure of 6 bar. Also, the liquid pressure decreases with continuous emptying of the storage chamber in correspondence with the decreasing spring action. Thereby, the characteristic of the spring process and also the dimensions of the particles vary during the emptying process, which is not desirable in practice.
A further proposal is known in which, instead of the spring actuated piston, the contraction force of a rubber hollow body with pumped in liquid, is utilized for atomizing the liquid. This proposal is not better than the other proposals. Here also the resulting liquid pressure is too small for acceptable atomizing, it decreases in dependence upon the emptying rate further.
Finally, a method is known in accordance with which the liquid is driven and atomized from a refillable pressure tight container after charging of an air pressure cushion via an outlet valve provided with a whirling spray head. In this arrangement the inner pressure also reduces and the spring characteristics also vary considerably during the emptying process, and the volume of the air cushion amounts to a multiple of the individual volumes of the liquid whereby the container is very heavy and inconvenient to use. This arrangement has a further disadvantage in the fact that, similarly to the mechanically operated intermittent atomizing pumps and the normal pressure atomizer packages, atomization of the liquid can be performed only in approximately vertical position of the package and position-independent atomizing is impossible. Finally, this method similarly to the above-mentioned two methods makes possible discharge of the product only in liquid form but not in foamed form.